Manufacture of a wiping or piston ring

ABSTRACT

This disclosure refers to improvements in the manufacture of a wiping ring comprising a grooved ring segment having an expander spring therein that presses radially all the exterior circumference of the segment against the wall of a surrounding cylinder and which radial pressure is graduated by the thickness and section of the expander. The segments are manufactured by compression, by means of a die-mold, the parts of which are partially or totally interchangeable.

United States Patent 1191 1111 3,758,929 Fabregat 1 Sept. 18, 1973 541MANUFACTURE OF A WlPlNG 0R PISTON 1,435,481 11/1922 Kistner .1 29/1 RING2,061,780 11/1936 Short 29/156.6 x 2,132,191 10/1938 Week, 11 29/156.6l

Manuel Punsola Fabregat, Portola St., 14, PO. Box 589, Barcelona, SpainFiled: Mar. 29, 1971 Appl. No.2 129,017

Inventor:

US. Cl 29/156.6, 29/l56.61, 29/l56.63, 72/352, 29/559 Int. Cl. 1323p15/06 Field of Search 29/156.6, 156.61, 29/l56.63, 557, 559; 72/352References Cited UNITED STATES PATENTS Primary Examiner-Charles W.Lanham Assistant ExaminerVictor A. Di Palma Attorney-Woodhams, Blanchardand Flynn [57] ABSTRACT 8 Claims, 16 Drawing Figures PATENTED SEP] 8I975 "sum 18F2 In ventor MANUFACTURE OF A WIPING OR PISTON RING Thisinvention refers to improvements in the manufacture of a ring segmentwith a groove therein to receive an expander spring that pressesradially all the exterior circumference of the segment against the wallof a surrounding cylinder and which radial pressure is graduated by thethickness and section of the expander. The present invention thusrelates to what is commonly referred to as a wiping ring or piston ring.The segments are manufactured by compression, by means of a diemoldhaving parts which are partially or totally interchangeable.

The improvements of this invention comprise a diemold integrated byseveral interchangeable pieces, and which improvements reflect in thesaving of complete die-molds and of the utilities, for the differenttypes, and forms of segments: compressor, scraper, greaserdegreaser.

For the manufacture of the segments, the first operation starts withcopper and its alloys in bars, laminating them or drawing them to themost adequate sections and thicknesses as required to use for thesucceeding pressure conformation of the segment to its type and form.

In continuation, in the second operation, the appropriate copper sectionis passed through a machine that cuts longitudinal fragments which arethen curved, forming open rings. The third operation is realized in adie-mold integrated by four interchangeable pieces; the upper movablepunch-base, the punch-disc with a groove-forming projection the ring onthe base, and the lower base. These interchangeable pieces allow theformation of several variations of grooves and engravings, and ofdesired dimensions.

To form an expander ring segment, the copper ring is placed in theappropriate die-mold for th type and form to be formed, and theassembled ring with the diemold is situated in a press to effect thepressing by punch blows, (consituted by the upper movable punchbase andthe punch disc), that in its succeeding return extracts the segment fromthe cavity of the mold, being held to the punch-disc and against theprotruding projection of same, from where the segment is removed byhand. The segment may be stamped with references such as commercialname, locality, number and other useful details which are all stamped ina single operation in the segment on the lower circumferential frontalpart of the groove.

The interchangeability of the die-mold parts permits a very extensiverange in terms of characteristics and dimensions of the ring segmentsbeing made.

The punch-disc realizes three operations simultaneously; it forms thegroove and the stamped reference engravings during the descent of thepunch, while the third operation consists in the extraction of the ringsegment from the interior of the mold as the punch-disc is movedupwardly and the press is stopped.

The segments after being formed, are susceptible to being machined ontheir two parallel planes or end faces in a machine with a magneticface-plate or electromagnet. For this purpose an open steel ring ofadequate section is placed in the inner groove of the segment, arrangingthem individually, also in series, in position on the magneticface-plate or electromagnet. In the center of the segment-ring of steelthere is positioned a ferric flat disc with a circular bevel, which discis of less thickness than the height of the segment and has a diameterso that it is supported on the steel ring so that when the electromagnetis actuated, the ferric disc steel ring receive the attraction of themagnetic plate or electromagnet, the whole becoming held together.

After rectifying or machining one parallel plane, the other parallelplane is rectified or machined in a similar manner to cause the segmentto have the thickness required.

The rectification may be performed be eliminating the open steel ring,but by placing the ferric metal disc in the center of the segment withthe disc being supported in the interior groove of the segment.

In order to facilitate the description, two sheets of drawingsaccompanies this memorandum, in which one case of realization has beenrepresented that is cited as an example.

In the drawings:

FIG. I shows in section the conjoint assembly of a die-mold with onering segment compressed therebetween.

FIGS. 2 to 5 show four variations of discs to form internal grooves, ascavities for housing the respective expansion springs, that may begraduated by thicknesses and sections.

FIG. 6 shows a plan view of the expansion spring.

FIG. 7 shows a plan view in section of a ring segment with the expanderspring housed in the groove for circumferential pressure to the segment.

FIGS. 8 to 11 show the possible sections of the expansion springs,circumferentially, interchangeable and graduateable by their thickness.

FIGS. 12 and 13 show respectively in section and plan, a mold base,whose upper compressor border has cavities with the object ofcompressing a non-ferric ring of greaser-degreaser type, that has canalsin one of its bases for the outlet of excess oil.

FIG. 14 represents a section of a segment of the greaser-degreaser typering with the expander spring housed in the groove.

FIG. 15 represents a detail in section of a segment ring prepared formachining of its axial end planes.

FIG. 16 represents a detail in section of a segment ring provided withan expander spring therein and prepared for machining of its axial endplanes.

Referring to the figures there illustrated a die assembly having anupper movable punch base 1 which is actuated by a press and coacts withan intermediate ring 2 that adjusts with a centering ring 4 and rests ona lower base 3 which is fixed to the immovable table of the press. Apunch-disc 5 is encased within lower base 3 and is fixed by screws 6 tothe upper movable punch base 1. The die assembly is used for forming acompressed ringlike segment 7 having an interior groove 8 for receivingtherein an expander spring 9 of shaped steel, which spring may have oneof many different cross sections such as circular l0, isosceles 11,square 12, and rectangular 13. A projection on the punch-disc 5 formsthe inner groove 8 in the segment 7. The projection 14 of FIG. 2 are ofa U-shaped form. However, other projection forms can be used. In FIG. 3,the projection 15 forms an isosceles groove. In FIG. 4, the projection16 forms a square groove. In FIG. 5, the twin projections 17 produce twointerior rectangular grooves in the compressed segment 7.

In FIGS. 12 and 13, the lower base has radial cavities 18 formedtherearound which, for the segment 7 being compressed, provide canalswhich are inclined toward the interior to provide better circulation ofthe excess oil from the greaser-degreaser.

In FIG. is seen a segment 7 which has housed within its groove 8 aferric disc 19 to be attracted by the magnetic plate or electromagnet ofa machine, such as a grinder. In FIG. 16, the ferric disc 19 rests onthe steel ring 9. In both cases, it is convenient that the disc 19 havea beveled border, and that its contact surface with the magnetic plateor electromagnet be in alignment with one of the planes or axial endfaces of the segment.

This invention, within its specialty may be carried into practice inother forms that differ in detail from the indicated form as an examplein the description. It may be therefore constructed in any form andsize, with the most adequate materials, all of which shall becomprehended within the spirit of the claims.

I claim:

l. Improvements in the manufacture of a wiping ring structure having agrooved ringlike segment containing therein a split ringlike expanderspring, comprising the steps of:

providing a barlike element of metal having a cross sectionalconfiguration consistent with the form and size of the segment which isto be formed; forming a predetermined length of said barlike elementinto an open or split ringlike member; providing a die assembly havingfirst and second relatively movable die sections, one of said diesections being adapted to support the split ringlike member thereon, theother die section having a disclike punch provided with an annularoutwardly extending projection for forming an annular groove in saidsegment;

positioning said ringlike element on said one die section when saidother die section is spaced therefrom;

pressing said ringlike member between said first and second die sectionsfor forming said segment therebetween with said projection resulting inthe for mation of an interior annular groove in said segment;

removing said segment from said die assembly; and

positioning a split ringlike expander spring within the interior grooveof said segment.

2. Improvements according to claim I, wherein the pressing together ofthe die sections causes the grooved segment to become attached to theprojection formed on said disclike punch, whereby said segment isremoved from said die assembly by causing said die sections to berelatively moved away from one another whereby said segment remainsattached to the projection associated with said other section, saidsegment then being expanded to enable removal of same from saidprojection.

3. Improvements according to claim 1, including the step of providingradially extending channels on one of the die sections in directcommunication with the ringlike member as positioned thereon, andpressing said die sections together for forming said segment and forforming channels in one of the surfaces of the segment.

4. Improvements according to claim I, further including the step offinishing the axial end faces of the segment after removal of same fromthe die assembly to cause the axial end faces to be planar and parallel,said finishing step including the sub-steps of positioning said segmenton a platelike magnetic or electromagnetic support member, and holdingsaid segment securely against said support member by means of a disc offerrite material positioned in the interior of said segment and havingedge portions adapted to engage said segment for holding said segmentsecurely against said support member.

5. Improvements according to claim 4, wherein a ringlike element isdisposed in the groove of said segment with said ringlike elementprojecting radially inwardly beyond the inner edge of said segment, andsaid disc having the edge thereof disposed in engagement with saidringlike element for holding said segment against said support member.

6. Improvements according to claim 4, wherein said disc has an axialthickness less than the thickness of said segment, and wherein theannular edge of said disc has a beveled surface thereon.

7. Improvements according to claim 1, wherein said one section of saiddie assembly includes a fixed lower base having a centering ring fixedlysecured thereto and coacting with said lower base to define a surface onwhich the ringlike member can be positioned;

wherein the other die section includes an upper movable base disposedopposite the lower base and having said disclike punch fixedly securedthereto and projecting downwardly therefrom toward the lower base, saiddisclike punch being adapted to extend into said centering ring, saidlower base and said centering ring being separable and said upper baseand said disclike punch being separable to permit the various componentsof the die assembly to be readily interchanged to pennit the size andcross section of the segment and of the groove therein to be readilyvaried.

8. Improvements according to claim 7, wherein the interior groove fonnedin said segment has a triangular or rectangular cross section, andwherein the expander spring has a triangular or rectangular crosssection, respectively.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION.

Patent No. 3 753 929 Dated September 18, 1973 Inventor(s) ManuelPunsola' Fa'bregat It is certified that error appears in theabove-identified patent and that said Letters Patent are herebycorrected as shown below:

On the title page, left hand column, between the lines numbered [21] and[52], please insert -[30] Foreign Application Priority Data, Spain,Application No. 378 595, filed April 4,

197o--. V i I Signed and sealed this 30th day of July 1974.

(SEAL) Attest:

MCCOY M. GIBSON, JR. c. MARSHALL'DANN Attesting Officer Commissioner ofPatents FORM PO-105O (IO-69) uscoMM-Dc scan-Pee I ".5. GOVERNMENTPRINTING OFFICE IDS 0-366-334.

1. Improvements in the manufacture of a wiping ring structure having agrooved ringlike segment containing therein a split ringlike expanderspring, comprising the steps of: providing a barlike element of metalhaving a cross sectional configuration consistent with the form and sizeof the segment which is to be formed; forming a predetermined length ofsaid barlike element into an open or split ringlike member; providing adie assembly having first and second relatively movable die sections,one of said die sections being adapted to support the split ringlikemember thereon, the other die section having a disclike punch providedwith an annular outwardly extending projection for forming an annulargroove in said segment; positioning said ringlike element on said onedie section when said other die section is spaced therefrom; pressingsaid ringlike member between said first and second die sections forforming said segment therebetween with said projection resulting in theformation of an interior annular groove in said segment; removing saidsegment from said die assembly; and positioning a split ringlikeexpander spring within the interior groove of said segment. 2.Improvements according to claim 1, wherein the pressing together of thedie sections causes the grooved segment to become attached to theprojection formed on said disclike punch, whereby said segment isremoved from said die assembly by causing said die sections to berelatively moved away from one another whereby said segment remainsattached to the projection associated with said other section, saidsegment then being expanded to enable removal of same from saidprojection.
 3. Improvements according to claim 1, including the step ofproviding radially extending channels on one of the die sections indirect communication with the ringlike member as positioned thereon, andpressing said die sections together for forming said segment and forforming channels in one of the surfaces of the segment.
 4. Improvementsaccording to claim 1, further including the step of finishing the axialend faces of the segment after removal of same from the die assembly tocause the axial end faces to be planar and parallel, said finishing stepincluding the sub-steps of positioning said segment on a platelikemagnetic or electromagnetic support member, and holding said segmentsecurely against said support member by means of a disc of ferritematerial positioned in the interior of said segment and having edgeportions adapted to engage said segment for holding said segmentsecurely against said support member.
 5. Improvements according to claim4, wherein a ringlike element is disposed in the groove of said segmentwith said ringlike element projecting radially inwardly beyond the inneredge of said segment, and said disc having the edge thereof disposed inengagement with said ringlike element for holding said segment againstsaid support member.
 6. Improvements according to claim 4, wherein saiddisc has an axial thickness less than the thickness of said segment, andwherein the annular edge of said disc has a beveled surface thereon. 7.Improvements according to claim 1, wherein said one section of said dieassembly includes a fixed lower base having a centering ring fixedlysecured thereto and coacting with Said lower base to define a surface onwhich the ringlike member can be positioned; wherein the other diesection includes an upper movable base disposed opposite the lower baseand having said disclike punch fixedly secured thereto and projectingdownwardly therefrom toward the lower base, said disclike punch beingadapted to extend into said centering ring, said lower base and saidcentering ring being separable and said upper base and said disclikepunch being separable to permit the various components of the dieassembly to be readily interchanged to permit the size and cross sectionof the segment and of the groove therein to be readily varied. 8.Improvements according to claim 7, wherein the interior groove formed insaid segment has a triangular or rectangular cross section, and whereinthe expander spring has a triangular or rectangular cross section,respectively.